Driveline vibration and engine miss

[KWhitlow]

I have a '95 2wd with automatic and 3. 54 rear end with 205,000 miles and have a vibration under load. The vibration only happens between 10 and 25 mph, with 1/2 ton or more in the bed and it is worse when going up hill. I have tried to lower the driveshaft carrier bearing (no difference). I have replaced the u-joints (seems to be a little better, but not much). The driveline shop says that the driveshaft is in good shape, the spring shop says that the pinion angle is perfect and the springs are good.
Where too next?!?
I also have noticed a "miss" in the engine lately. I don't notice it under load-unless thats my vibration..... hummmm, but when I stop, the engine will sometimes start to shake,then it will straighten out and idle smooth for about 30 seconds then start to shake again. This ony happens every once in a while.
The truck is stock, and has just been serviced (filters fluids)
Any ideas? #ad


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'95 2500 2x4, Auto, 3. 54, 205,000 miles, Just starting to have fun!

 

[Steve Roseman]

What kind of RPMs are you running when you get the vibration?

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'95 2500 Ext. Cab, 2wd 3. 54 limited slip, auto, TST #6 230/605 plate, BD low stall T. C. , K&N air filter. I have to tell you, I LOVE MY TRUCK!!!!!!

 

[Andy Redmond]

are you sucking air at low rpms (recent filter change) maybe the gasket isn't sealing?

Otherwise check the fuel psi for a worn lift pump, overflow valve , fuel line restriction, weak return line, etc. .

Also run some Cummins or other good injector cleaner to make sure one isn't acting up. .

On your vibration, could your auto transmission be about to give up. . sounds like you have competent folks advising on the u-joints, angles etc. .

Good luck
Andy

 

[KWhitlow]

Originally posted by Steve Roseman:
What kind of RPMs are you running when you get the vibration?

I notice it from 1250 rpm until I pass 25 mph (2000+/-). It seems to be more speed sensitive than rpm.

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'95 2500 2x4, Auto, 3. 54, 205,000 miles, Just starting to have fun!

 

[KWhitlow]

Originally posted by andy redmond:
are you sucking air at low rpms (recent filter change) maybe the gasket isn't sealing?

Otherwise check the fuel psi for a worn lift pump, overflow valve , fuel line restriction, weak return line, etc. .

Also run some Cummins or other good injector cleaner to make sure one isn't acting up. .

On your vibration, could your auto transmission be about to give up. . sounds like you have competent folks advising on the u-joints, angles etc. .

Good luck
Andy

I will check the filter and the fuel psi - Thanks, I still have A LOT to learn about diesels.

I just serviced the transmission (transmission flush, new filter, adj. bands, and checked pressures). The fluid "looked" OK, the PO told me that he had not done anything to it in the past 50000 miles :EEK:but the pan and the fluid were pretty clean. The pressures were all within specs.



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'95 2500 2x4, Auto, 3. 54, 205,000 miles, Just starting to have fun!

 

[Steve Roseman]

I know it's kind of an odd poke in the dark, but how old are the shocks?
You mentioned it was more speed sensitive than rpm sensitive, that made me think it may be suspension not motor.
At 110k my truck would get a shake going down the highway but would stop after slowing down a little then speeding back up. Come to find out, it still had the original shocks on it.
I would still run the injector cleaner through it as mentioned, can't hurt anything.

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'95 2500 Ext. Cab, 2wd 3. 54 limited slip, auto, TST #6 230/605 plate, BD low stall T. C. , K&N air filter. I have to tell you, I LOVE MY TRUCK!!!!!!

 

[illflem]

Sometimes one bad tire will make the type of vibrations you speak of. Check to see if you have lost any balance weights or have a bad spot on a tire.